make native includes RIOT posix compatible
further clean up / filtering for cpu
add debug information to chardev_loop
Merge pull request #470 from LudwigOrtmann/chardev_debug

add debug information to chardev_loop
Merge pull request #468 from LudwigOrtmann/native_includes

make native includes RIOT posix compatible
Start POSIX net [pnet] module
Implement file descriptor table

Needed for pnet
Implementation of close()
Define stdin, stdout and stderr
Wrap RIOT socket API
Add auxilary headers